Whether we’re overcome with joy at a beautiful wedding ceremony, or we just watched a sad Humane Society commercial, our bodies respond in much the same way.

Many of us who cry or are on the verge of crying often feel a lump-like sensation in the throat. As there isn’t an actual lump forming in our throat, where does the sensation come from? The answer may lie in the autonomic nervous system.

To understand why we get lumps in our throats, we must first talk generally about why we cry, and what happens inside our bodies when we do.

The exact reason we cry is sort of a mystery, but there’s strong evidence to suggest that crying is a form of non-verbal communication that we’ve evolved as incredibly social creatures.

This means that crying serves as a way for us to tell people around us of our emotional state and, therefore, elicit their support. As Bec Crew explains:

“Emotional tears kick in during times where you feel a loss of control, and scientists think that, along with other physical reactions such as an increased heart rate and slower breathing, our stress hormone- and endorphin-laden tears are there to quickly stabilise your mood, and perhaps act as a very obvious signal to those around us that we may be in need of some cuddles”.

These intimate, tearful moments when we are comforted by another person help us solidify our personal relationships, which are vital for us humans.

Making stronger bonds isn’t the only suspected reason. Some researchers think that crying was once a way for us to submit to attackers.

By showing signs of submission, an attacker – likely another human – would pity us and leave us be (or at least alive). Obviously, this is generally not a good defense against, say, a lion attack, because they couldn’t care less about your emotions.

With that in mind, what happens internally – on a physical level – when we start to get emotional?

As Nick Knight explains for The Independent, your autonomic nervous system – the overarching system that controls other nervous systems like the sympathetic nervous system – kicks into gear, and causes a bunch of different reactions inside your body depending on the circumstances.

This is the same system that controls your ‘fight or flight’ response along with other unconscious body functions like digestion. When this system switches to hyper mode, it first sends out oxygen all over your body to make it easier for you to punch something in the face, or run away in the opposite direction to safety.

To spread oxygen to all of your muscles, your body must first breathe it in. In an effort to take in more air, the nervous system tells the glottis – the opening in your throat that ushers air into lungs without taking food with it – to stay open for as long as possible. In other words, your throat opens wider than normal because a bigger opening means more air.

You don’t actually feel your glottis opening wide. If you did, everyday life would feel awfully strange. What you do feel, though, is muscle tension caused by your body trying to keep your glottis open even when you swallow.

Normally, when you aren’t crying, your glottis opens and closes when you swallow all day long. This ensures that food and spit go one way and air goes the other, with no mix-ups in between.

But, when you cry or are on the verge of crying, your glottis is trying to stay open, but gets forced close every time you swallow. This tension messes with the muscles in your throat, giving the sensation of a lump.

The lump feeling is actually referred to as globus sensation, and it happens to everyone in these stressful situations. Normally, this feeling dissipates quickly once you calm down and your glottis goes back to functioning like it used to.

As for tears, the process happens very much the same way: your nervous system prompts tear production.

Obviously, as anyone who has ever cried knows all too well, crying also causes a slew of other side effects, like a runny nose, red face, and possibly even a headache. These are all due to the fact that your tear ducts are so closely connected to your sinuses that they basically turn you into a ball of snot.

So pretend, if you will, that someone is breaking up with you (sorry, it’s not real, don’t worry!). When the news hits, your nervous system kicks into gear and triggers your fight or flight response. Your body starts trying to circulate more oxygen to your muscles while also triggering your tear ducts.

As your start to cry, you also start to breathe heavier to get more oxygen into your system. To compensate for this, your glottis is held open. At this point, you’re really crying. Tears are streaming down, and mucus is building in your nose and throat, causing you to swallow.

As soon as you do, the muscles in your throat get confused and close your glottis, which is essentially being propped open, and that strain causes the lump inside your throat.

There you have it! That lump in your throat is actually just your body being kind of awesome, transforming you into a better breathing machine.